Nice, clear pics. I still have difficulties telling the difference between SAE and CAE at the fish store. From your pics, the most apparent difference seems to be that the black line runs unbroken from tail to nose in the SAE and from tail to eye in the CAE. Is this noticeable in juvenile specimens, and are there any other differences that you could point out?

The CAE is a suckermouth fish. That is the most defining characteristic. The SAE as no apparent sucker for it's mouth. What most people have problems distinguishing are the Flying Fox and False Siamensis when compared to the true SAE. This page has some drawings about the differences.

The only real way I can tell the difference is to look at the black line and fins. The true SAE line goes all the way through the end of the tail. The False Siamensis does not. The Flying Fox will have coloring on its fins, and the true SAE will have clear fins other than the ribbing.

There used to be a better website with the differences and real pictures. I think the False also has a suckermouth. The SAE has only two whiskers coming from the top of his mouth. The Flying Fox has four I believe. I have a store near me that labels them Flying Foxes, but they're SAEs. There are 30+ there at the store. I should sell them if they're so hard to come by in the United States like all the articles state.

If they're larger, the whiskers help. The SAE has a pair of whiskers that come from the top of it's mouth. The Flying Fox should have a pair on top and a pair on the bottom. It's tough to see in a store tank that has lots of these things moving everywhere, and sometimes stores mix batches together.

The coloration on the fins I have a tough time on seeing as what is in the background affects the perceived coloration.

In larger SAEs, the stripe should be a zig zag on the edges, not straight. I think that's the best sign to tell, but you can't see that until the fish are larger from what I've read.

I was lucky and was able to see all these things pretty clearly when I was in the store.